Leak stopper for condenser tubes



8- 0, 1955 s. PENNELLA 2,716,428

LEAK STOPPER FOR CONDENSER TUBES Filed March 3, 1953 5 2 FIG.I 9 5 Io I F G 8 SAMUEL PENNEL A INVENTOR. 44.2144 1) United States Patent LEAK STOPPER FOR CONDENSER TUBES Samuel Pennella, Pompton Lakes, N. J.

Application March 3, 1953, Serial No. 340,122

1 Claim. (Cl. 138-97) This invention relates to surface condensers employed for condensing exhaust steam in power plants, etc., and more particularly to leak stopping inserts for insertion into a condenser tube for preventing leakage through openings formed in the tubes by corrosion or erosion.

The cooling water flowing through the tubes of a surface condenser causes failure of the inlet ends of the tubes, due to impingement, erosion, and electro-chemical corrosion, resulting in the eating away and perforation of the tube, causing leakage. Such action has been found by experience to be most severe in close proximity to the inlet end of the tube.

It is an object of the present invention to provide an insert or leak-stopping sleeve for insertion into the eaten-away end of the tube for effectively sealing any leaks therein, consequently prolonging the life of the tube as well as eliminating for a practice period of time the necessity for retubing the condenser.

It is necessary, to stop such leaks and prevent further deterioration of the tube, that the leak stopping insert fit the interior of the tube in fluid tight engagement, and necessary also that the act of forcing the insert into the tube not disrupt or break the corroded tube. An object of the present invention is to provide a novel, practical insert which can be readily forced into a corroded tube without disrupting or rupturing the tube structure, which will effectively stop all leaks in the tube and one which will not impair the heat transfer efliciency of the condenser by adversely aifecting the cooling water flow through the tubes.

Another object of the present invention is to provide leak stoppers for condenser tubes which are constructed of relatively heavy metal to increase the useful life of the leak stoppers and which leak stoppers have one or more sections of non-frangible material which will not crack either in handling or when subjected to shocks, etc., encountered during the operation of a surface condenser, and which material is of sufficient hardness to permit machining, yet will swell when wetted so as to tightly fit within the condenser tube and form a fluid tight joint between the leak stopper and the condenser tube. sufficient area or areas of the swellable material is used to provide a tight seal but which seal, including only a part of the length of the metal tubular insert may be broken by force so that the leak stopper may be driven from a condenser tube when it becomes worn or corroded and replaced by a new one.

The present invention is an improvement on the leak stoppers for condenser tubes described and claimed in my prior Patents 2,262,042 of November 11, 1941 and 2,484,904 of October 18, 1949.

With these and other objects in view, as may appear from the accompanying specification, the invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawings, showing a leak stopper for condenser tubes of a preferred form embodying the invention, and the features forming the invention will be specifically pointed out in the claim.

2,716,428 Patented Aug. 30, 1955 'ice In the drawings:

Figure 1 is a side elevation of the improved leak stopper for condenser tubes.

Figure 2 is a longitudinal section taken on the line 22 of Figure 1.

Figure 3 is an end view of the leak stopper.

Figure 4 is a cross section through a frangible material inlet head member employed in the leak stopper.

Figure 5 is a cross section through the leak stopper taken on the line 5-5 of Figure 2.

Figure 6 is a view partly in side elevation and partly in section of a modified form of the leak stopper.

Figure 7 is a view partly in side elevation and partly in section of another modified form of the leak stopper.

Figure 8 is a view partly in side elevation and partly in section of a further form of the leak stopper.

Referring more particularly to the drawings, the improved leak stopper includes a tubular insert 1 of metal which in the present invention is considerably thicker than the metal sleeve parts of the tubular inserts of the leak stoppers of my prior patents above referred to. The purpose of making the metal of the tubular insert thicker is to increase the active life of the leak stoppers.

In the construction shown in Figures 1 to 5 of the drawings, the inlet end 2 of the metal tubular insert 1 is flared slightly and has the sleeve portion 3 of the inlet head member 4 inserted therein. The inlet head member 4'is constructed of hard, non-frangible material which will not crack or break either in handling or when subjected to shocks, etc., encountered during the operation of a surface condenser. The material is of sufiicient hardness to .per-' mit it to be accurately machined, yet it will swell or expand when wetted so as to fit tightly within the expanded inlet end 2 of the tubular insert 1, and form a fluid tight seal therewith. The sleeve portion 3 of the inlet head member 4 terminates in a shoulder 5 against which the end of the tubular insert 1 abuts. Outwardly of the shoulder 5 the inlet head member 4 flares outwardly forming a radially extended annular portion adapted to fit snugly within the counterbore of a condenser tube sheet (not shown) and against the end of a condenser tube (not shown) into which the leak stopper is inserted. i The internal diameter of the sleeve portion 3 of the inlet head member 4 is slightly less than the internal diameter of the tubular insert 1. The difference in these diameters is such as to prevent particles of coke or the like from passing through the inlet head member into the tubular insert 1 where it might become lodged and so that any piece of coke or any foreign material which will pass through the bore of the inlet member 4 will pass freely through the tubular insert 1 and the condenser tube (not shown) in which the insert is inserted. The bore of the inlet head member 4 flares outwardly as shown at 6 in the outwardly flared portion of the inlet head member to provide fluid flow guide into the leak stopper.

The outlet end of the leak stopper is tapered to form substantially a knife edge, indicated at 7, so as to prevent abrupt changes in water flow as it issues from the insert and prevent the formation of eddies. A short distance inwardly of the knife edge 7 is an annular recess 8 formed in the outer surface of the tubular insert 1 and a sleeve or ring 9 of hard non-frangible fibrous material which will swell when wetted is inserted in this recess so that when the leak stopper is inserted in a condenser tube the sleeve 9 will swell to form a fluid tight joint between the leak stopper and the'condenser tube near the outlet end of the leak stopper so as to prevent back flow of water along the tubular insert 1. In constructing the tubular insert, it's outlet end has its diameter reduced the depth of the recess 8 andthe nonfrangible fibrous sleeve 9 is then inserted on" this reduced end after which the terminus of the tubular insert is mounted upon the inlet end of the tubular insert 1' and its outermost end fits or abuts against the annular flange 11. The outlet end of the tubular insert 1' has a recess 8' formed therein in which is seated a sleeve 9' of non-frangible fibrous material which will swell when wetted. The sleeve 9' corresponds to the sleeve 9 shown in Figure 1 and is held in place in the recess by the annular flange 10' which corresponds to and is made the same as the flange 10.

Figure 7 shows a further modification of the leak stopper which is the same as the structure shown in t Figure 6 of the drawings, including the sleeve 12 mounted about the inlet end of the tubular insert 1" and abutting against the annular flaring flange 11 formed on the inlet end of the tubular insert 1". The tubular insert 1", however, does not have the swellable sleeve 9' mounted thereon nor on its outlet end.

The structure of the leak stopper shown in Figure 8 is a slightly diflFerent modification of the structure shown in Figure 6. In this modification the tubular insert 1a has its inlet end flared outwardly as shown at 11a to provide an annular flange which will engage against the end of a condenser tube (not shown) and in the counterbore of a condenser tube sheet (not shown). The outlet end of the tubular insert It: has an annular recess 8a formed therein in which a sleeve 9a of non-frangible fibrous material, which will swell when wetted, is inserted. The recess 8a and the mounting of the sleeve 9a therein is carried out in the same manner as described in connection with the form of the invention shown in Figure 1 of the drawings.

it will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown, but that they may be widely modified within the invention defined by the claim.

What is claimed is:

Means for stopping leaks in a perforated tube of a surface condenser comprising a tubular insert, said insert tapering to a knife edge at its outlet end and flared slightly on a uniformly increasing diameter from a predetermined point inwardly of its inlet to its inlet end, an inlet head member including a sleeve portion inserted into the flared inlet end portion of the tubular insert and having a reduced outside diameter to receive the flared inlet end portion of the insert whereby the outer surface of the insert will lie flush with the outer surface of the inlet head member, said inlet head memher having an enlarged inlet end for engagement with a condenser tube sheet, said tubular insert has a por tion of its outer surface cut away for a predetermined distance inwardly of its outer end, and a sleeve of material which will swell when wetted seated in said cut away portion and having its outer surface flush with the outer surface of the tubular insert.

References Cited in the file of this patent UNITED STATES PATENTS 184,790 McConnell Nov. 28, 1876 768,477 McKinley Aug. 23, 1904 2,225,615 Bay Dec. 24, 1940 2,262,042 Pennella Nov. 11, 1941 2,310,927 Bay Feb. 16, 1943 2,445,273 Kennedy July 13, 1948 2,449,616 Pennella Sept. 21, 1948 2,484,904 Pennella Oct. 18, 1949 2,500,601 Buttler, Ir. Mar. 14, 1950 2,620,830 Schultz Dec. 9, 1952 FOREIGN PATENTS 450,984 Great Britain July 28, 1936 

